The present invention generally concerns a cylinder head for air-compressing, self-ignition internal combustion engines with several cylinders, and more particularly to such a cylinder head constructed so that a structurally stiff inclusion of an auxiliary combination chamber is achieved.
European Patent Specification (EP-PS) 00 62 143 discloses connecting auxiliary combustion chambers on the inside of a sidewall of the cylinder head housing in a cylinder head of above-noted general type of construction. It does not provide a further connection to the top of the cylinder head, which runs substantially parallel to the bottom of the cylinder head. In consequence, the auxiliary combustion chamber does not substantially contribute to the structural stiffness of the cylinder head.
Accordingly, an object of the present invention is to construct a cylinder head in such a way that a structurally stiff inclusion of the auxiliary combustion chamber is achieved in the cylinder head housing.
It is another object of the present invention to provide a compact cylinder head structural shape in association with simple assembly.
The invention achieves these and other objects by constructing the cylinder head so that the auxiliary combustion chambers are immediately adjacent to a cylinder head top.
Because of the shaping of the cylinder head provided by certain preferred embodiments of the present invention, the bottom of the cylinder head and the top of the cylinder head are joined to form a composite casting by the housings of auxiliary combustion chambers. By this arrangement, the auxiliary chambers are stiffened and, simultaneously, the housings of the auxiliary combustion chambers act as support columns by which the cylinder head housing is in itself further stiffened. Because of the support column effect of the chambers, it is possible to arrange these in a substantially isolated manner in the coolant space so that at least good cooling of the upper part of the chambers is achieved by the flow of coolant around them on all sides.
In addition, the connection locations between the top of the cylinder head and the auxiliary combustion chambers are suitable for accepting a tapped hole for an injection nozzle, which can therefore be located within the outline of the housing so that a compact cylinder head design is achieved. Moreover, the fact that the top of the cylinder head is at an angle achieves good drainage of the lubricating oil from the control space into the crank case.
A compact design of the cylinder head is achieved by positioning the tapped holes for the injection nozzle at an angle.
Moreover, depressions in the wall housing above the auxiliary combustion chambers form recesses for receiving the injection nozzles in an isolated manner to provide good access to the injection nozzles from the outside, which substantially simplifies assembly and maintenance work.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.